I need help with sed in bash

I've worked for hours to try to get my .docx & .xlsx files to be associated with my MS Office that was installed with PlayOnLinux. I'm finding out that PlayOnLinux is great for installing things, but not so great for actually using them.

Anyway, I finally figured out how to use mimeopen -d to create a custom command for playonlinux to associate files in Nautilus. The only problem was that it didn't work if the filename or folder name had spaces. So I found where someone put the following code in the PlayOnLinux shortcut scripts for Word and Excel. That code makes it work with spaces, but a side effect of this code is that it replaces all 'C's with 'Z's in the file and folder names. Can anyone tell me exactly what this is doing, and maybe how to get it to work with spaces, but not replace the 'C's? Here's the code:

Code:

"$(echo "$@" | sed -e 's:C:Z:' -e 's:/*/:\\:g')"

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